Aeronautical propeller



Oct 26 192a. 1,0435% 5, A. REED AERONAUTICAL PROPELLER Filed Dec. 2, 1924 ATTORNEY Patented Oct. 26, 1926.

, UNITED STATES PATENT OFFICE.

SYLVANUS REED, on NEW YORK, N. Y., AssIeNoE TO THE REED PROPELLER co.

INC.,' or NEW YORK, N. Y., A CORPORATION or NEW YORK AERONAUTICAL PROPELLER.

Original application filed June 22, 1923, Serial No. 570,139. Divided and this application filed December 2, 1924. Serial No. 753,482. p i

This invention relates generally to propellers for aeronautical use and particularly to propellers of the metal type, including such as those which I have described and claimed in my U. S. Letters Patent No. 1,463,556, dated July 31, 1923, and No. 1,518,410, granted Dec. 9, 1924, upon application for patent Serial No. 570,139, filed June 22, 1923, and this application is a division of said latter application.

A general object of the present invention is to provide a multiple construction of propeller having a plurality of separate blades ofthe general type described and claimed in my patent and pending application hereinabove referred to.

The present invention includes the use of a plurality of radially extending blades having connecting means attached to the root p0rtions of the blades for holding them in operating position in opposition to the radial pull of centrifugal force.

Another feature of the invention includes an interhooked engagement of projections or lugs on the separate blades with each other so that the direct engagement of the blades with each other provides a mutual resistance to centrifugal force. There are also other features of the invention which will be hereinafter referred to.

Certain forms of'my improved propeller and certain preferred methods of constructing the same are hereinafter set forth and il' lustrated in the drawings; Wherein Figure 1, is aside view of a two blade propeller embodying one form of my invention. e

Figure 2, is a side view of the propeller shown in Fig. 1, the view being taken at right-angles thereto.

Figure 3, isa side view of a modification and Fig. 4, is a cross-section thereof.

As stated in my said patents, while in most cases it is perhaps preferable to make my improved propeller in one continuous piece of metal from tip to tip, in certain cases I obtain the superior blade sections described without making the propeller in a single piece. In such cases and. as herein shown the blades are made separate and are united directly one with the other by a cen tral junction in the form of a lap or other suitable engagement of the continuation preferably of the leading edge of one blade with a continuation of the trailing edge of the other, and such uniting engagement may take any convenient form possessing the proper strength to resist centrifugal force and. torque, while the shaft attaching means is constructed to accommodate itself to the particular form of union or. lap engagement of the blades.

In the drawings, l.v show two diiferent constructions of the separate blades which are united at the axial region.

In Figs. land 2, the blades 40 and 41, have their bases or inner ends formed With a central shaft-receiving opening 42, which is shown in the form of a notch which provides two extensions or prongs 43 and 44, which are so disposed and proportioned as to be placed in overlapping engagement and united by bolts 45. The openings 42 in the base ends of the respective blades register with each other and provide a suitable opening for the passage of the drive-shaft 11, to which the two-part blade structure is attached in any of the suitable ways hereinabove described, the seat or attachingfiange being shaped to conform to the peculiar shape of the union means at the blade base. The prongs 43 and 44, of the respective blades, overlap in a reverse manner upon the o posite sides of the blades as indicated in ig. 2, which shows the prong 43 of blade 40, and the prong 44 of blade 41, upon the same face of the propeller. In Figs. 1 and 2, and also Fig. 3, T have indicated bolt-receiving holes 46 for receiving the bolts which also pass through the attaching flange, shown in said prior application.

In Figures 3 and 4, ll show the separate blades 40 and 41*, with their ends forked so as to span the drive-shaft 11. The forks or prongs 47 and 48, of the blade 40 have their ends bent'in oppositedirectipns at right angles as at 49 and 50, While the prongs 51 andv 52, respectively, of the blade 41, have their ends bent in a similar manner at53 and 54, thereby providing hooked projections adapted to be interlocked in overlapping contact as shown. A bolt 55, is passed through the interhooking ends 47 and 52, of

the respective blades, while a bolt 56, is passed through the other inter-hooked ends 48 and 51, respectively. The opening or notch 56, between the prongs 47 and 48, of

blade 40, and the notch 57 between prongs 51 and 52, of blade ll form a circular opening for receiving the drivc-shaft 11, as indicated in Fig. 3. In this structure the blades are well fortified against centrifugal action, and they are attached to the drive-shaft in any suitable way.

In the structures shown herein, it will be understood, of course, that the separate blades are constructed like the blades shown in my said prior application for patent, and have the same formation between the part 7 and tip 5, and the part 8 and tip 6, so that all the advantages of such blade shape is present in these structures. 7

In the structure herein shown, I have indisated a nut 58,\\'l1i *.l1turns on a thread on the propeller shaft 11, for the purpose of holding the propeller on the shaft and preventing its moving longitudinally thereon, while a key locks the two'parts in fixed relation.

While the constructions referred to produce. a continuation of the leading edge of one blade with the trailing edge of the other the invention is not limited to this relation of parts. I wish to be understood as not limiting my invention to the particular forms herein shown and described, as it is manifest that various modifications may be made in the different parts,\vithout, however, departing from the spiritcof my invention.

Having thus describedmy invention, what I claim and desireto secure by Letters Patent is p 1. In an aeronautical propeller, a plurality of separable blade members, the root portions of the blades being providedyvith hook members formed for inter-engagement, whereby the radially extending blades will mutually resist the radial outward pull of centrifugal force.

2. In an aeronautical propeller, radially extending blades having'their root portions provided with facial projections interhooked with one another to resist the separating action of centrifugal force.

3. In an aeronautical propeller, radially extending blades having interengaged laterallyextending flanges on their inner ends.

4. In an aeronautical propeller, a set of radially extending blades having bifurcated inner ends, said bifurcated ends overlapping each other and having laterally extending interengaged flanges to resist the radial pull of centrifugal force.

5. In an aeronautical propeller, radially extending blades having broad forked inner ends, said forked ends of the blades spanning the driving means and interlapping each other, and said forked ends having laterally extending interhooked flanges.

6. In an aeronautical propeller, separable blades provided with laterally extending hook members at the blade root portions, the hook members of one blade being formed to be placed in interengaging relation with the hook members ofanother blade, and means for fastening the hook members together.

7. In an aeronautical propeller, separable blades provided with forked root portions whereby the 'fork prong members may be placed in straddled relation to the propeller shaft, and said prong members having a hook formation whereby the prong members of one blade may be placed in interengaging relation with the hook prong members of another blade.

8. In an aeronautical propeller, separable blades provided with forked root portions whereby the fork prong members may be placed in straddled relation to the driving means, and the prong members on each blade being bent laterally in opposite directions whereby the prong members of one-blade may be. placed in interengaging relation bases which connection sustains the entire stress of centrifugal force, and shaft attaching means to transmit torque and thrust, each of which propeller blades has two blade terminals forked elongations bent in opposite directions overlapping and interengaging with the adjacent corresponding bladeelongations at a desired pitch angle, the interengaging portions being provided with means to maintain them rigidly in position. 1

10. In an aeronautical propeller, separate blades having their inner ends or root portions provided with prongs constructed and arranged so that when the blades are assembled the space between said prongs provides a passage for a driving member, and said prongs of one blade overlapping those of another, one upon one side and one upon the other and mutually resisting radial stress, and means for securing said parts together.

11. In an aeronautical propeller, separate blades having their root portions formed with bifurcated ends engaging each other so as [to sustain the entire stress of centrifugal force, said overlapping connection being deformed and the leading edge of each blade being disposed in continuation of the trailing edge of its adjacent blade;

12. In an aeronautical propeller, separate blades having their root portions formed with bifurcated ends overlapping each other in operative engagement so as to sustain the entire stress of centrifugal force, each of said blades being provided with a hole for attaching a driving-connection and disposed in the median plane of the blade a substantial distance from the axis of rotation.

SYLVANUS A. REED. 

